Priming mixture



a srras rear recs PETER ARONSON, OF BRIDGE-PORT, CONNECTICUT, ASSIGN'OR '1'0 REMINGTON ARMS COMPANY, INC., A CORPORATION OF DELAWARE PRIMING MIXTURE Ho Drawing. Application filed June 14,

This invention relates to primer compositlons or mlxtures and particularly to a prlming mixture which contains no ingredients 10 combustion thereof, commercial priming compositions include three classes of ingredients. The first is an initial explosive, or force producing ingredient; the second a substance which on decomposition yields a large quang tity of oxygen. The third is a fuel or substance to be oxidized.

I With the advent of-modern smokeless and semi-smokeless powders, it became necessary to greatly increase the heat and pressure generated upon the explosion of the priming mixture, thus necessitating a very powerful and dependable oxidizing agent. Potassium chlorate has been quite universally used for this purpose. The combustion of this substance, however leavesa residue of very hygroscopic potassium chloride, which substance solidifies at a comparatively high temperature, and is driven by the high pressures prevailing within the gun barrel into microscopic fissures and indentations in the surface from which it cannot be removed by mechanical swabbing, or by the universally used nonaqueous gun cleaning compositions. Due to its hygroscopic character, the potassium chloride subsequently absorbs moisture and corrodes the gun barrel, even after it has been cleaned and oiled with great care.

For this reason, the need for a priming composition which does noiIi nclude potassium or other chlorates has ong been felt, and many other oxidizing agents have been proposed and tried.

The preparation of a priming composition, however, is a delicate and diflicult undertaking, involving many problems besides the yielding of .a non-corrosive residue.

While the ingredients must be capable of reacting with extreme rapidity when struck a sharp blow they must also remain uncombined in an intimate mixture for an indefinite 1926. Serial No. 116,032.

time. They must also be incapable of reactmg with the metal of the primer cup or shell case. They must likewise remain stable'and activ e for an indefinite time underextreme conditions of temperature and humidity.

In the past, various oxidizing nitrates, for

example barium nitrate, have been proposed is used the propelling charge tends to ignite slowly, rather than to detonate sharply, or if it does detonate, the explosion is retarded. Cartridges in which the propelling charge burns or explodes late are respectively known as squibs and hangfires,

In order to eliminate hangfires in nitrate primers it is sometimes desirable to add an ingredient which will accelerate the reaction. For thus purpose an initial explosive, such as mercury fulminate, has been proposed. The present invention, however, contemplates the use as an oxidizer in primers of a true peroxide which isv sufiiciently nonhygroscopic to remain stable and active under the adverse conditions heretofore mentioned, a true peroxide being understood to be one which reacts with water or acids to form hydrogen peroxide. Prior to the investigation leading to this invention little had been published or known regarding this class of compounds. The number of them at present known to exist is limited, and the related elements are generally found in the third column of the tables of the periodic system.

The ingredients of priming compositions.

position of t e elements in the table. The' peroxides of the alkali earth metals are quite hygroscopic, but their hygroscoplcity decreases with increase in the atomic welghts.

The known peroxides of the less basic metals in the right hand group of the third column of the table show a similar variation, and each of these peroxides is less hygroscopic than the peroxide of the alkali earth metal in the same row or series of the table.

The present invention com rises the discovery that the peroxides o the elements other than the alkali earth metals, in the third column of the periodic table, are suitable oxidizing ingredients for priming compositions. While the exact composition of such peroxides may be regarded as somewhat doubtful, their existence has been recognized and they may be prepared by methods which have been described inchemical literature. See for example Chemical Abstracts, vol. 6, page 43. Of these the peroxide of cadmium of other elements of this group are also suitable. The superiority of cadmium peroxide may be due in part to its lower hygroscopicity. While these substances may be used alone, their use in conjunctionwith an oxidizing salt, such as an oxidizing nitrate, is preferred. With barium nitrate, for example, the peroxide accelerates combination, making the firing of the cartridge quick and certain. Moreover the composition is not liable to deteriorate under ammunition transportation and storage conditions. The proportions of the ingredients may be varied thru wide limits. A typical highly'successful rim fire composition has approximately the following composition:

. Percent Mercury fulminate 37 .4. Lead sulpho-cyanate 9. 3 Barium nltrate 23. 4 Cadmium peroxide 10.3 Grlass -r. 18.7 Gum arabic A 0.9

ter fire ammunition is A similar composition adapted for cen Per cent Mercury fulminate.. 35.4 Lead sulpho-cyanate 8.9 Barium nitrate 36. 5 Cadmium peroxide 10. 3 Antimony sulphide 8. 9

- The invention, however, is to be understood as contemplating the use in priming compositions, of true peroxides generally, and particularly true peroxides ofthe elements, exelusive of the alkali earth metals, in the third column of the periodic table, with any other ingredients, as well as all equivalent compositions which fall within a broad interpretation of the appended claims.

. What is claimed is:

'1. A priming mixture containing cadmium peroxide. 1 2

2. A riming mixture containing a' nitrate and ca mium peroxide.

is particularly desirable, althoughperoxides column of the periodic table, and 9.

3. A primin mixture containing barium nitrate and ca mium peroxide.

4. A priming mixture containing mercury fulminate, barium nitrate, and cadmium peroxide.

5. A primin mixture containing mercury fulminate, cad mium peroxide, barium nitrate and a fuel.

6. A priming mixture having approximately the following composition:-

Percent Mercury fulminate 3 Lead sulphocyanate 9. 3 Barium nitrate 23. 4; Cadmium peroxide 10. 3 Glass 18.7 Gum arabic 0.9

of an element in the right hand group of the third column of the periodic table.

11. A priming composition containing a combustion initiator with a peroxide of an element in the right hand group of the third second oxidizing ingredient.

12. A priming composition containing barium nitrate, and a peroxide of an element in the right hand group of the third column of the periodic table. I c

13. A priming composition containing a combustion initiator, barium nitrate, and a peroxide of an element in the right hand group of the third column of the periodic table, and a fuel.

14. A riming'mixture containing a comlfmsltion initiator, cadmiumperoxide, and a 15. A priming mixture containing a com PETER R. ARONSON. 

